The present invention relates to a semiconductor device and a method of manufacturing the semiconductor device. Specifically, the invention can be preferably applied to a semiconductor device including a nitride semiconductor.
A field effect transistor including a nitride semiconductor can perform high frequency operation and has properties of high withstand voltage and low on-resistance. The field effect transistor including the nitride semiconductor is therefore used in a switching power supply or an inverter of a power electronics system, and contributes to reductions in size and weight of a peripheral passive element due to high frequency operation and a reduction in loss due to low on-resistance.
For example, Japanese Unexamined Patent Application Publication No. 2015-115582 (JP-A-2015-115582) discloses a technology on a normally-off field effect transistor having a voltage clamp layer, in which the voltage clamp layer is electrically coupled to a source electrode by a coupling part extending up to the voltage clamp layer.
Japanese Unexamined Patent Application Publication No. 2013-58791 (JP-A-2013-58791) discloses a MOSFET including a buffer layer on a substrate and a lower semiconductor layer made of p-GaN on the buffer layer. The MOSFET includes a carrier transit layer on the lower semiconductor layer, carrier supply layers formed on the carrier transit layer and separated by a recess portion, a gate insulating film formed so as to cover the surface of the carrier transit layer in the recess portion, and a gate electrode formed on the gate insulating film.